This invention relates to solar energy collection, and in particular to the attachment of torque arms to the drive shafts (or torque tubes) used to tilt solar collectors about a pivot axis so that the solar collectors can track the motion of the sun relative to the earth.
In general terms, solar collector installations have an array of solar collector assemblies including solar collectors, also called solar collector modules, supported above a support surface, typically the ground. The solar collectors are typically photovoltaic solar collectors. The solar collectors are often mounted to the drive shaft by frame or other support members. The drive shaft, sometimes referred to as a torque tube or torque member, defines a pivot axis. A tracker drive system, also called a tilt assembly, is typically used to rotate or rock the rows of solar collector assemblies about their tilt axes to keep the photovoltaic modules as square to the sun as possible. Usually, the rows are arranged with the tilt axes of the solar collector assemblies disposed in a north-south direction, and the tilt assemblies gradually rotate the one or more rows of solar collector assemblies throughout the day from an east-facing direction in the morning to a west-facing direction in the afternoon. The solar collector assemblies are brought back to the east-facing orientation for the next day.